Coated fabric materials and methods and compositions for producting same



United States Patent signor to said Arnold No Drawing. Filed May 17, 1960, Ser. No. 29,583 7 Claims. (Cl. 117-161) This invention relates to colored plastic coating compositions, to methods of applying these compositions to textile fiber materials, and to the new and improved fiber materials resulting therefrom. More specifically this invention relates to latex coating compositions derived from thermoplastic emulsion polymers and to methods of treating textile fiber materials whereby improved fiber materials are obtained.

Many attempts have been made to develop colored thermoplastic coatings for textile fiber materials or structures for a variety of applications. It has been sought to produce coatings which would be inexpensive and easily applied from an aqueous dispersion. However, complete success has not been obtained since the coatings produced have been lacking in one or more of the following necessary properties:

(1) Resistance of the coloring agent to water bleed- (2) Low cost;

(3) Flexibility of application so as to obtain a wide range of colors and a wide range of stiffness of the coat- (4) Freedom of the coating from chipping off;

(5) Ability to run the coated fabric on package fabricating machinery without slippage;

(6) Proper processing performance when applied from an aqueous emulsion;

(7) Freedom from mark-off of the color when the coated fabric is pressed against a paper or other surface, that is, the coating must neither stick nor show marks of the coloring matter;

(8) Good bonding of the threads on net or scrim fabrics, and

(9) Better appearance, that is, bright and clean looking rather than dull or fuzzy.

By way of example, it is known that a fabric such as cotton net or scrim fabric can be coated with a mixture of starch, urea formaldehyde precondensate, and a water insoluble dye or pigment, which mixture is then baked on the fabric. However, the fabric which results is opaque, dull in appearance, and fuzzy.

It has been generally considered by those skilled in the art that if, for example, a continuous filament rayon net or scrim were employed as the base fabric and coated with a colored thermoplastic, the desirable properties referred to above would be obtained, that is, a bright, clear, colored fabric without fuzz. Attempts to adapt the starch, urea formaldehyde, and dye compositions, noted above, to rayon fabrics were unsuccessful because these compositions would not bond well enough to the rayon, and because they give a dull, non-lustrous coating.

It was then attempted to dye the rayon fabric with wash-fast dyes and to put on top of this a thermoplastic coating composition consisting of a plasticized polyvinyl acetate. However, this met with technical failure since it was not possible to handle the net fabric through the successive wet operations necessary to obtain a fast dyeing and to apply the coating without undue loss of width and uniformity of the structure. It is necessary that the finished fabric have the net construction in perfect alignment.

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Attempts to color a plasticized polyvinyl acetate emulsion with a direct dye produced a coating from which the dye bled badly in water. It is necessary that the treated fabric withstand rain, or water from other sources without bleeding. Moreover, the dye also tended to coagulate the specific polyvinyl acetate emulsion employed resulting in a cloudy, non-illustrous coating.

Another attempt was made using plastic dyes which are insoluble pigments. Although the dyes were low in cost per pound, such high concentrations were required to obtain the depth of shade needed that the cost was prohibitive. In addition it was not possible to obtain complete resistance to water bleeding with them.

It is, therefore, an object of this invention to provide a coating composition for textile fiber materials which will impart to these materials the desirable properties set forth above.

It is also an object of this invention to provide a method for applying the aforementioned composition to textile fiber materials.

A further object of this invention is to provide novel colored plastic coated fiber materials of improved appearance and resistance to Water bleeding.

Another object is to provide yarn in the form of warps seized with a colored thermoplastic size resistant to water bleeding.

Other objects and advantages of the invention will be apparent from the following description.

According to the present invention it has been discovered that a satisfactory coating for fiber materials, which possesses substantially all of the desirable properties noted above, can be prepared by combining a mixture of an appropriate thermoplastic copolymer emulsion of requisite stability, a selected water soluble dye, and a dye fixing agent.

More specifically the thermoplastic copolymer emulsion contemplated by this invention is one that is not coagulated by the dye or by the dye fixing agent when they are mixed with it. The more commonly used types of thermoplastic emulsion polymers are often coagulated, especially when the resulting composition is heated as in drying, by heavy metal salts such as aluminum or zirconium acetate and by quaternary ammonium compounds which are used as dye fixing agents and by many water soluble dye compositions. This is because these emulsion polymers are prepared with protective colloids which are often coagulated by these various materials. They are emulsified with polyvinyl alcohols which in themselves are often coagulated by these agents. Summarizing, the present invention involves the selection of an emulsion-polymer which is compatible with the dye and dye fixing agent and does not coagulate or precipi- .tate during drying. Unacceptable emulsion-polymers tend to coagulate into large agglomerates when the mixture is prepared, or, if not then, during drying. The

coating formed in the fiber by these coagulated polymers is non-uniform and unsatisfactory.

Emulsion polymers can now be prepared which resist coagulation by these coloring agents and dye fixing agents. These emulsion polymers fall in the general class known in the trade as borax stable emulsion polymers. They generally are emulsified with a combination of a hydroxy ethylcellulose and a small amount of surface reactive agent. However, there are some polyvinyl alcohol emulsified emulsion polymers which have sutficiently care fully chosen emulsifying systems such that they also are stable to these dyes and dye fixing agents. Further, some of the borax stable emulsion polymers available on the market are not stable to these dyes and dye fixing agents due to improperly chosen emulsifying systems.

Whether an emulsion polymer is sulficiently stable for use in the present coating compositions can be readily determined by the following testing procedure which consists of mixing the emulsion polymer with the intended dye and with the intended dye fixing agent and heating. It is then examined for coagulation, if necessary, by placing a drop between two microscopic slides and squeezing them together. The emulsion can also be examined for coagulation by dilution with water. The film formed can be examined for coagulation with transmitted light. In either instance a coagulated emulsion will form a cloudy dull film. Even though a stable dispersion is formed by the resin emulsion, the dye, and the dye fixing agent at room temperature, the dispersion must not coagulate during drying on the fiber.

Representative emulsion polymers which can be employed in the present invention are:

The thermoplastic emulsion can be prepared by emulsion polymerization or by emulsification of the resin polymer as is, if possible, or in a suitable solvent by means of suitable emulsifying agents. It must be resistant to coagulation on mixing with the dye and with the dye-fixing agent even when the mixture is subsequently heated. The prime function of the thermoplastic resin emulsion is as a coating and binder capable of bonding fiber structures together with a coating and binding which is colored in a manner resistant to water bleeding.

A specific example of a preferred emulsion polymer is one containing 55 percent solids of a copolymer of about 75 percent vinyl acetate and 25 percent dibutyl fumarate, copolymerized after emulsifying the mixture of monomers in a solution of hydroxyl ethyl cellulose. Polymerization is carried out at 70-80 C. with a conventional catalyst system based on potassium persulfate. The resulting polymer (hereinafter designated as Polymer 1) forms a flexible film on a fabric treated therewith and does not chip off or flake off when the coated fabric is processed on package or other fabricating machines. The stiffness of the film on the fabric may be varied by adjusting the ratio of the two monomers. For example, increasing the amount of the dibutyl fumarate increases the flexibility of the film and vice versa.

It is also possible to use vinyl acetate homopolymers by adding an appropriate plasticizer before emulsifying in the manner described above or by stirring them into the emulsion after polymerization. However, this procedure is less satisfactory since the addition of the plasticizer results in a film which is less resistant to bleeding.

In general any water soluble dye of the class of sodium salts of azo compounds, i.e., direct dyes and acid dyes,

I} can be employed in the present invention. such as the following are preferred:

Direct Red 1 (Color Index 22310) Direct Blue 22 (Color Index 24280) Direct Black 38 (Color Index 30235) Direct Orange 26 (Color Index 29150) Direct Green 1 (Color Index 31315) Although acid dyes can be used, they are more difficult to fix to water bleeding.

Suitable agents for fixing the dyes to water bleeding are: basic aluminum acetate, barium acetate, magnesium acetate, zirconium acetate, aluminum formate, aluminum sulfate, zirconium nitrate, copper sulfate, copper acetate, stearyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, cetyl pyridinium bromide, and the like.

Similar agents or products which are used for fixing direct dyes so as to prevent bleeding such as the cationic urea formaldehyde copper complexes, can be employed in the present process. However, the preferred products are the metallic acetates noted above since they are inexpensive, exhibit a good fixing action, and do not seriously affect the shade or light fastness of the dyes used.

The manner in which the novel coating compositions are applied to textile fiber materials will be more particularly illustrated by the following examples. However, it is to be understood that these examples are not limitative but merely illustrative of the present invention.

Example I Direct dyes A bath is prepared by dissolving sixteen ounces of Direct Red 1 (Color Index 22310) in two gallons of water. This is mixed with stirring into one hundred twenty gallons of Polymer I, described above, to which is added fourteen ounces of basic aluminum acetate in one gallon of water. This mixture is stirred thoroughly and is then padded onto a scrim fabric. The fabric is at this point passed under a roller in the bath and then run over a roller about five or six feet above the bath and then back through the squeeze roll. The fabric is thereafter dried under tension on a hot tenter frame at 300-350 F. The resulting fabric has an excellent appearance, and the plastic coating is observed to be firmly bonded and free from water bleeding.

Example I] The procedure of Example I is repeated except twelve ounces of Direct Orange 26 (Color Index 29120) is dissolved in two gallons of water and then mixed with twelve gallons of Polymer II which is similar to Polymer I, described above, but the ratio of vinyl acetate to dibutyl fumarate is 85:15. To this is added four and one-half pounds of a 20 percent solution of zriconium acetate dissolved in one gallon of water. Upon completion of the padding and drying steps, the same excellent results noted in Example I above are obtained, but the resulting fabric is somewhat stiffer.

Example III The procedure of Example I is repeated with the same excellent results except that the dye is Direct Green 1 (Color Index 31315) and the emulsion polymer is a copolymer of a mixture of percent vinyl acetate and 20 percent ethyl acrylate.

Example IV The procedure of Example I is repeated with the same excellent results except that the dye is Direct Blue 22 (Color Index 24280) and the emulsion polymer is copolymerized from a mixture of percent vinyl acetate and 15 percent dibutyl maleate.

Example V A warp of 300 denier bright rayon was sized by passing it through a bath consisting of twelve ounces of Direct Blue 22 (Color Index 24280) in two gallons of water, twelve gallons of Polymer II (see Example II above), four and one-half pounds of a .20 percent solution of aluminum acetate dissolved in one gallon of water and thirty gallons of water. The resultant warp was found to be coated to the extent of about of its weight with the colored thermoplastic film and the color was resistant to water bleeding. An upholstery fabric of a warp faced construction was woven from this warp.

Example VI A non-woven fabric was coated by spraying with the mixture of Example I so as to add 10 percent of solids to the weight of the fabric. Thereafter the fabric was continuously dried in a conventional hot air oven. The resulting fabric was free from water bleeding and the plastic was firmly bonded to the fabric.

It is to be noted in the preceding example that the fabric could also be coated by knife coating. The concentration or add-on of plastic coating can be readily adjusted by techniques well known in the art such as by adding conventional thickeners (sodium polyacrylate, hydroxy ethyl cellulose, and the like); by varying the concentration of the resin being applied to the fabric, and by adjusting the knife on the coating machine. Moreover, conventional upholstery fabrics can be coated on their face or back in the same manner to give a continuous colored plastic coating resistant to water bleeding.

Various modifications can be made in the novel process of this invention without departing from the spirit and scope of the inventive process disclosed herein. For example, it may be desired to modify further the plastic film, which is coated on the fabric, so as to reduce tackiness or surface slipperiness by adding various materials. As it is not economical to remove coning oils from the yarn after the fabric is woven, it is necessary to counteract the slippery surface which they impart to the resin coating. This can be done by adding clay or whiting to the composition. It also may be desired to impart additional resistance to blocking or sticking by adding a water soluble wax such as a stearic acid ester of polyethylene glycol or a stearic acid alkylol amine condensate to the bath.

Representative of such a modified procedure, which employs the compositions and process of this invention, is the following example:

Example VII Sixteen ounces of Direct Blue 22 (Color Index 24280) are dissolved in two gallons of water and then mixed with 20 gallons of Polymer I to which is added five pounds of 20% aluminum acetate solution in one gallon of water. To this mixture is then added seven pounds of clay dispersed in a small amount of water with tetra sodium pyrophosphate and one pound of the stearic acid monoester of polyethylene glycol 400. A scrim fabric is then padded and dried as in Example I above with the same excellent results noted. The concentrations of the clay and the glycol ester are low enough such that they do not interfere with the luster and the clarity of the coating.

The coating compositions and process of this invention can also be used to produce a continuous coat on a closely woven scrim fabric or on a conventional fabric such as a sheeting. The base fabric may already be dyed or may be white.

It is also possible to produce this coating with just as satisfactory results by using two baths. In this case the emulsion polymer and the dye would be applied on the first pad following which the fabric would go through a second pad containing additional emulsion polymer and aluminum acetate. Other additives, such as the clay and the insoluble waxes of Example III above, would be put 6 in the second pad. Illustrative of this modification is the following example:

Example VIII Two baths are prepared. The first bath consists of 15 ounces of Direct Red 1 (Color Index 22310) dissolved in two gallons of water and added to 15 gallons of Polymer I described above. The scond bath consists of one and one-half pounds of basic aluminum acetate dissolved in one gallon of water and added to 15 gallons of Polymer I. To this was added 10 lbs. of clay and one pound of the condensation product of stearic acid and diethanolamine in water soluble form. The padding and drying steps of the scrim fabric were similar to Example I above.

Fiber materials which can be treated by the colored plastic compositions of this invention include:

(1) Closely woven and knitted fabrics from natural or synthetic spun staple yarn, such as cotton, rayon, polyester fibers, jute and the like.

(2) Closely woven and knitted fabrics from continuous filaments natural or synthetic fibers such as rayon, nylon, cellulose acetate, polyester fibers, natural silk and the like.

(3) Net or scrim constructions for bagging, decorative fabrics, and garments from spun and continuous filament yarns.

(4) Non-woven fabrics from cotton, cellulose acetate, rayon, and the like.

(5) Sheet fiber structures such as paper from wood pulp or which may be reinforced with cotton or short fibers of nylon, polyester and other synthetic fibers.

(6) Warps for which the coating will serve as the size and will in addition be colored in a manner resistant to water bleeding.

By way of specific illustration net fiber materials coated with the colored plastic compositions of this invention have been found to be admirably suited for bagging. For example, fruit and vegetable bags made with the colored plastic compositions of this invention retain their appearance and undergo no color bleeding even when exposed to water.

While the illustrative embodiments of the invention have been described hereinbefore with particularity, it will be understood that various other modifications will be apparent to and can readily be made by those skilled in the art without departing from the scope and spirit of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and description set forth herein but rather that the claims be construed as encompassing all the features of patentable novelty which would be treated as patentable equivalents thereof by those skilled in the art to which the invention pertains.

What we claim is:

1. A composition of matter comprising a water soluble dye of the class consisting of direct dyes of sodium salts of azo compounds and acid dyes of sodium salts of azo compounds; a dye fixing agent, which will fix the dye against water bleeding, selected fro mthe group consisting of aluminum acetate, zirconium acetate, barium acetate, magnesium acetate, aluminum formate, aluminum sulfate, zirconium nitrate, copper sulfate, copper acetate, stearyl trimethyl ammonium chloride, cetyl ammonium bromide, and cetyl pyridinium bromide; and a thermoplastic polymer emulsion stable to the dye and fixing agent and selected from the group consisting of polyvinyl acetate; copolymers of polyvinyl acetate with dibutyl maelate, dibutyl fumarate, methyl acrylate, ethyl acrylate, butyl acrylate, ethyl methacrylate, ethyl hexyl acrylate, vinyl caprate, vinyl stearate, and acrylonitrile, respectively; polymers of vinyl chloride; co-polymers of vinyl chloride with vinyl acetate, ethyl acrylate, and vinyl stearate, respectively; polymers of ethyl acrylate; and copolymers of ethyl acrylate with acrylonitrile, methyl methacrylate, acrylic acid and styrene, respectively.

2. The composition of claim 1 in which the dye is a direct dye, the dye fixing agent is basic aluminum acetate, and the emulsion polymer is a copolymer of vinyl acetate and dibutyl fumarate.

3. The composition of claim 1 in which the dye is a direct dye, the dye fixing agent is basic zirconium acetate, and the emulsion polymer is a copolymer of vinyl acetate and dibutyl furnarate.

4. The composition of claim 1 in which the dye is a direct dye, Lhedye fixing agent is aluminum formate, and the emulsion polymer is a copolymer of vinyl acetate and ethyl acrylate.

5. The composition of claim 1 in which the dye is a direct dye, the dye fixing agent is basic aluminum acetate, and the emulsion polymer is a copolymer of vinyl acetate and dibutyl maleate.

6. A process of treating a fabric with a thermoplastic colored resin so as to produce a fabric resistant to water bleeding comprising passing the fabric through a treating bath containing the composition of claim 1 and thereafter heat drying the treated fabric at a temperature of 5.- about 300 to 350 F. for the purpose of bonding the composition to the fabric.

7. The treated fabric resulting from the process of claim 6.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Cyriax: Synthetic Polymer Dispersions, Chemistry and Industry, pp. 895-899, September 13, 1952.

Knecht et al.: Textile Printing, pp. 205-208, 731, Charles Grifiin and Co., London, 1952. 

1. A COMPOSITION OF MATTER COMPRISING A WATER SOLUBLE DYE OF THE CLASS CONSISTING OF DIRECT DYES OF SODIUM SALTS OF AZO COMPOUNDS AND ACID DYES OF SODIUM SALTS OF AZO COMPOUNDS; A DYE FIXING AGENT, WHICH WILL FIX THE DYE AGAINST WATER BLEEDING, SELECTED FROM THE GROUP CONSISTING OF ALUMINUM ACETATE, ZIRCONIUM ACETATE, BARIUM ACETATE, MAGNESIUM ACETATE, ALUMINUM FORMATE, ALUMINUM SULFATE, ZIRCONIUM NITRATE, COPPER SULFATE, COPPER ACETATE, STEARYL TRIMETHYL AMMONIUM CHLORIDE, CETYL AMMONIUM BROMIDE, AND CETYL PYRIDINIUM BROMIDE; AND A THERMOPLASTIC POLYMER EMULSION STABLE TO THE DYE AND FIXING AGENT AND SELECTED FROM THE GROUP CONSISTING OF POLYVINYL ACETATE; COPOLYMERS OF POLYVINYL ACETATE WITH DIBUTYL MAELATE, DIBUTYL FURMARATE, METHYL ACRYLATE, ETHYL ACRYLATE, BUTYL ACRYLATE, ETHYL METHACRYLATE, ETHYL HEXYL ACRYLATE, VINYL CAPRATE, VINYL STEARATE, AND ACRYLONITRILE, RESPECTIVELY; POLYMERS OF VINYL CHLORIDE; CO-POLYMERS OF VINYL CHLORIDE WITH VINYL ACETATE, ETHYL ACRYLATE, AND VINYL STEARATE, RESPECTIVELY; POLYMERS OF ETHYL ACRYLATE; AND COPOLYMERS OF ETHYL ACRYLATE WITH ACRYLONITRILE, METHYL METHACRYLATE, ACRYLIC ACID AND STYRENE, RESPECTIVELY.
 6. A PROCESS OF TREATING A FABRIC WITH A THERMOPLASTIC COLORED RESIN SO AS TO PRODUCE A FABRIC RESISTANT TO WATER BLEEDING COMPRISING PASSING THE FABRIC THROUGH A TREATING BATH CONTAINING THE COMPOSITION OF CLAIM 1 AND THEREAFTER HEAT DRYING THE TREATED FABRIC AT A TEMPERATURE OF ABOUT 300 TO 350*F. FOR THE PURPOSE OF BONDING THE COMPOSITION TO THE FABRIC. 